Omega-6 fats have been accused of fueling inflammation, a claim that has been escalated by recent social media conversations and online chatter. But new data from the Framingham Offspring Study suggest the opposite may be true, particularly in the case of linoleic acid (LA), the most common omega-6 fat in the American diet and the primary fat in most seed oils.
In a cross-sectional analysis of 2,022 U.S. adults, researchers evaluated red blood cell (RBC) levels of omega-6 fatty acids in relation to three well-established biomarkers of systemic inflammation: interleukin-6 (IL-6), C-reactive protein (CRP), and tumor necrosis factor receptor 2 (TNFR-2). The study, published in the journal Nutrients, found that RBC LA content was inversely associated with IL-6 and CRP, even after adjusting for demographic, lifestyle, and dietary variables. That is, the higher the LA content, the lower the inflammation.
“Our results suggest that LA is more likely to be anti- than pro-inflammatory, and the present efforts to reduce its intake are ill advised,” the authors wrote.
The study — partly funded by SNI Global with support from the United Soybean Board — also examined total omega-6 fatty acids, which showed similar patterns. However, LA, which accounts for the majority of omega-6 intake in the diet, appeared to be the primary driver. The conversion of LA to arachidonic acid (AA) in the body is typically cited as the basis for claims about inflammation, but RBC AA content was not associated with CRP or TNFR-2 and was instead found to be inversely related to IL-6.
Plant-based oils (sometimes referred to as seed oils now) such as soybean, sunflower, safflower, and corn oil, are leading dietary sources of LA. These oils are predominantly polyunsaturated fatty acids (PUFA) and have been shown to reduce LDL cholesterol when used in place of saturated fats. Although omega-6 PUFA are often criticized in popular discourse, the study’s findings reinforce the notion held by most scientists that LA acid does not promote inflammation at typical dietary levels. The findings of the current study are consistent with clinical and long-term observational studies, which consistently show that linoleic acid does not have a proinflammatory effect.
This focus on mechanistic speculation, rather than relying on robust research, has fueled a growing wave of public skepticism about seed oils. This newly published analysis not only adds to the scientific consensus refuting claims about harmful effects but also indicates that oils like soybean and sunflower oil are beneficial.
The authors conclude by saying their findings support dietary recommendations to replace saturated fat with unsaturated fat, particularly PUFA.
For health professionals and researchers, this study offers timely reassurance that LA, as consumed in typical dietary patterns, supports rather than undermines health. It also underscores the need to evaluate nutrition claims in the context of peer-reviewed evidence rather than unverified online discourse.
Read the full study:
Red Blood Cell Omega-6 Fatty Acids and Biomarkers of Inflammation in the Framingham Offspring Study
This blog is sponsored by SNI Global and U.S. Soy.
